Tuesday
September 2, 2014

Homework Help: pre-calc

Posted by Jessica on Thursday, April 12, 2007 at 8:26pm.

Can someone check my work please?

Convert each polar equation to a rectangular equation. Then determine the graph's slope and y-intercept.
( I'm going to type 'x' instead of theta )
r sin(x- pi/4)=2

r(sin(x- pi/4))=2
r(sinx*cos pi/4 - sin pi/4*cosx)=2
r(sqrt2/2*sin x - sqrt2/2*cos x)=2
sqrt2/2*rsin x - sqrt2/2*rcosx=2
(sqrt2/2*y - sqrt2/2*x=2)^2
1/2(y^2) - 1/2(x^2)= 4
1/2(y^2 - x^2)=4
y^2 - x^2= 8
(y^2= 8 + x^2) sqrt
y= sqrt(8) + x

slope= 1
y-int= sqrt 8

miraculously, you made two major errors that cancelled each other out, and you came up with the right answer.

line 4 can be reduced to √2y - √2x = 4
which convert to y = -x + √8
so your answer is right

why are you squaring the equation in line 5???, you had it!!!

When you square an equation you CANNOT just square each term.
Your left side should have contained 3 terms.
Then in line 9 you cannot take the square root of each term!

eg. √(16+9) is not equal to √16 + √9

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

pre calc.Math - Please help me any one of these please! Thank You to any one r=...
Pre-Calc - Convert r=1+3sin2x from a polar equation to a rectangular equation.
Pre-calculus; urgent ! Please help ! - 1.Graph the polar equation r=3-2sin(theta...
Math - For the equation y = -6x, what is the slope and y intercept? The formula...
Math - For the equation y = -6x, what is the slope and y intercept? The formula...
Trig/pre-calc - r=8cos(theta)+5sin(theta), convert the polar equation into a ...
precalculus - convert the equation y^2 = 2x -x^2 into polar form. convert the ...
My Daughter Stacy needs help in math plz help! - You have to find the x and y ...
Calculus please help ! - 1.Graph the polar equation r=3-2sin(theta) 2. Find the ...
Math ! Please Help ! - 1.Graph the polar equation r=3-2sin(theta) 2. Find the ...

Search
Members